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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
521

CAD-Integrated Life Cycle Assessment in Product Development : Evaluation in a Technical Development Context

Hultgren, Petrus, Smärgel, Pontus January 2023 (has links)
In order to reduce the environmental footprint of products, companies turn to Eco-design and associated tools. Life cycle assessment (LCA) is a holistic and quantitative tool that is widely accepted in companies, but it is too extensive to apply in product development; as an alternative, simplified versions are more suitable. By utilising CAD models of components, material data and a database, weight can be calculated and LCA data estimated. This thesis aims to evaluate the feasibility of utilising CAD-integrated LCA software in product development process and explore the barriers in doing so. A case study was conducted to evaluate the software Sustainable Innovation Intelligence by thoroughly describing the tool, the database used as well as the product life cycle management (PLM) system used. Two research questions have been formulated regarding the barriers and to what extent they can be overcome using the new CAD-integrated tool. The first one is answered by a literature review, where 22 barriers were identified and related to different sociotechnical levels, while the second is answered by using pattern matching following the case study. The evaluation covers human and technical aspects of the tool itself, what is required by the practitioner, as well as additional aspects to consider when implementing the tool in a company. The final result shows that 11 of the barriers are to some extent being overcome by the tool. While showing promise, the novelty of the software makes it immature and lacking full functionality, while requiring a lot of the practitioner in terms of LCA specific knowledge.
522

Ganzheitliche Bewertung von Wärmepumpensystemen

Bumann, Felix, Panitz, Felix, Felsmann, Clemens 24 March 2023 (has links)
Es erfolgt ein ganzheitlicher Vergleich der Systeme Luftwärmepumpe und Sole-Wasser-Wärmepumpe für ein Bestandsgebäude. Für die Bewertung der Umweltfreundlichkeit bzw. Klimaschutzwirksamkeit werden die CO2-äquivalenten Treibhausgasemissionen (THG-Emissionen) und der nicht-erneuerbare Primärenergiebedarf (KEV) der Systeme bilanziert. Für den fairen Vergleich werden Systeme mit investkostengleichen Gesamtinvestitionen gebildet, indem die Luftwärmepumpe zusätzlich um eine PV-Anlage ergänzt wird.
523

Sustainable Development of Neurofeedback Device / Hållbar utveckling av neurofeedback-enhet

De Geer, Daniel January 2021 (has links)
Mendi (Mendi, 2020) is a company founded to provide accessibility of brain enhancement training to the ordinary citizen, they reside in Stockholm, Sweden. The Mendi brain training headset has been developed to aid users using neurofeedback. This technology allows for display of brain activity in real-time, and the implementation of the Mendi headset is meant to teach the user how to better regulate their brain activity. With the possibility to start sustainable design in conjunction with the market release of the product, this project was initiated to serve the future progress of sustainable development. The work conducted in this paper is based on development methods used to assess the current state of the product as well as the phases of the product life cycle in which sustainable solutions can be applied. The methods used are life cycle assessment, material research and analysis, design for disassembly, assessment of production and use, market research of similar products, and research literature on modern methodology in sustainable design. Quantitative assessment was created through comparative analysis using the program CES EduPack (Granta Design, 2019), where data of the current product is used as a reference throughout. This is combined with research findings of best practice in sustainable development of products; tools used in the development contained concept generation in the form of sketching, CAD, and 3D printing. The result is described quantitatively in the parts where data has been available, it is also presented through life cycle scenarios, giving examples from assumptions based on research of empirical studies and results from design methods used throughout. The result present scenarios of a redesigned product and how this differ from the existing prototype in the form of economic and, environmental sustainability. The final concept was created through guidelines of eco design, built around the previous work of the product for plausible implementation in upcoming development. The product uses snap-fits to enable disassembly, press-fit to avoid any mixing of materials, has reduced amount of materials and contains materials that lower the life cycle CO2 emission and energy use. Economic factors are similarly assessed, quantitative analysis of life cycle costs combined with assumption driven scenarios showing potential gains and losses that could occur from said changes. Combined, the results are meant to work as a guideline for any future endeavors made in the field of sustainable development by Mendi and their partners. / Mendi (Mendi, 2020) är ett företag som grundades för att ge den vanliga medborgaren tillgång till hjärnförbättringsträning, de är bosatta i Stockholm, Sverige. Mendi-headsetet för hjärnträning har utvecklats för att hjälpa användare genom något som kallas neurofeedback. Denna teknik möjliggör visning av hjärnaktivitet i realtid, och implementeringen av Mendi-headsetet är tänkt att lära användaren att bättre reglera sin hjärnaktivitet. Med möjligheten att starta hållbar design i samband med marknadsutsättningen av produkten inleddes detta projekt för att tjäna framtida framsteg inom hållbar utveckling. Arbetet i denna artikel bygger på utvecklingsmetoder som används för att bedöma produktens nuvarande tillstånd samt faserna i produktlivscykeln där hållbara lösningar kan tillämpas. De metoder som används är livscykelbedömning, materialforskning och analys, design för demontering, bedömning av produktion och användning, marknadsundersökning av liknande produkter och forskningslitteratur om modern metodik i hållbar design. Kvantitativ bedömning skapades genom jämförande analys med programmet CES EduPack, där data för den aktuella produkten används som referens genomgående. Detta kombineras med forskningsresultat om bästa praxis för hållbar utveckling av produkter; verktyg som användes i utvecklingen innehöll konceptgenerering i form av skisser, CAD och 3D-utskrift. Resultatet beskrivs kvantitativt i de delar där data har kunnat erhållas, det presenteras också genom livscykelscenarier, vilket ger exempel från antaganden baserade på forskning om empiriska studier och resultat från designmetoder som använts genomgående. Resultatet presenterar scenarier för en nydesignad produkt och hur denna skiljer sig från den befintliga prototypen i form av ekonomisk och miljömässig hållbarhet. Det sista konceptet skapades genom riktlinjer för eko-design, byggd kring produktens tidigare arbete för sannolik implementering i kommande utveckling. Produkten använder snäppanpassningar för att möjliggöra demontering, presspassning för att undvika blandning av material, har minskat antal olika material och innehåller material som sänker livscykeln CO2-utsläpp och energianvändning. Ekonomiska faktorer bedöms på liknande sätt, kvantitativ analys av livscykelkostnader i kombination med antagandedrivna scenarier som visar potentiella vinster och förluster som kan uppstå från tidigare nämnda förändringar. Sammantaget är resultaten avsedda att fungera som en riktlinje för framtida utveckling som görs inom området hållbar utveckling av Mendi och deras partners.
524

An integrated approach to environmentally conscious design and manufacturing

Goan, Meng-Jong Kuan 03 October 2007 (has links)
The problem addressed in this research was to develop an approach for the simultaneous green design of products and associated manufacturing processes including demanufacturing concerns. We propose a generic approach called Integrated Environmentally Conscious Design and Manufacturing (IECDM) which can be applied to address problems in the ECDM domain. IECDM incorporates environmental considerations into the engineering design process, thereby increasing a product's total life-cycle value (including its end-of-life value) as experienced by the customer, manufacturer, and society, while simultaneously reducing impacts on the environment caused by that product and its manufacturing processes. IECDM is a novel integration of Quality Function Deployment (QFD), Life-Cycle Assessment (LCA), Multiple Criteria Decision-Making (MCDM), and Cost-Benefit Assessment (CBA). The focus is on process, based on modification of the traditional QFD methodology to incorporate environmental issues and green product-design decisions through the life cycle design activities of synthesis, analysis, and evaluation. This dissertation presents a QFD-based IECDM approach, a mathematical CBA model, and an IDDS (Integrated Design Decision-Support) framework with a design-flow-chart application for incorporating environmental criteria into product and process eco-design. The IECDM problem is defined as: given the customer and environmental requirements, develop an integrated approach for green product design that results in maximization of the product's total life-cycle value (TLCV). Initially. through investigation in the field of ECDM, we specified a clear ECDM domain within Industrial Ecology. Then. we proposed various state-of-the-art techniques that were used to implement ECDM in the literature. After we defined the IECDM problem. we developed an integrated approach that led to a generic QFD-IECDM methodology for dealing with problems in the ECDM domain. Finally, for implementing the proposed methodology, we developed a tentative IODS framework to encourage long-term development followed by an example. / Ph. D.
525

Att bygga hållbara småhus som privatperson : En studie om materialval, kostnad och hinder

Dahlfors, Patricia, Näsström, Sofia January 2024 (has links)
Bygg- och fastighetssektorn representerade år 2021 21,7% av Sveriges inhemska utsläpp (Boverket, 2023a). Detta visar på en stor potential i branschen att minska klimat- och miljöpåverkan som går i linje med FN:s hållbarhetsmål. Företag arbetar aktivt med att bygga mer hållbart, men privatpersoner som bygger småhus har också möjlighet att bidra till en positiv förändring. Detta projekt syftar till att jämföra olika materialval i klimatskalet i småhus ur ett hållbarhetsperspektiv. Ett av de analyserade alternativen är ett befintligt nybyggt exempelhus (småhus A) med mindre vanliga materialval, som har jämförts mot ett konventionellt sätt att bygga svenska småhus på (småhus B) som framtagits genom en enkätundersökning. Frågorna i enkätundersökningen har baserats på befintlig litteratur om vanligt förekommande material som skickats till 53 byggföretag, varav 31 företag svarat. Ett egenutvecklat förslag (småhus C) har även tagits fram med målet att förbättra materialvalen ur ett ekonomiskt och miljömässigt perspektiv.   För att kunna utvärdera miljömässig hållbarhet har en livscykelanalys genomförts där utsläpp av koldioxidekvivalenter studerats under delar av bygg- och användningsskedet. Material- och transportkostnad har även analyserats ekonomiskt med hjälp av en livscykelkostnad. För att ett förslag ska vara hållbart måste den ekonomiska och miljömässiga aspekten balanseras, som kan uppnås om lösningen är miljövänlig samtidigt som den är ekonomisk försvarbar. Det egenutvecklade förslaget är baserat på resultatet av livscykelanalysen och livscykelkostnaden från småhus A och B, samt utefter befintliga hinder som undersökts genom litteratur och ett frågeformulär som skickats ut till några aktörer som är med och påverkar byggprocessen. Två fiktiva småhusmodeller som utgår från den genomsnittliga boarean av småhus i Sverige togs fram, som resultatet av studien applicerades på för att ge en uppfattning om totalt CO2eq utsläpp och kostnad för ett småhus.   Resultatet visade att småhus B är det billigaste alternativet, men även det som genererar störst koldioxidutsläpp. För 105 000 eller 124 000 kr mer för material- och transportkostnad för de framtagna fiktiva småhusen med area 122 kvm, kan 7,1 respektive 12,1 ton koldioxidekvivalenter sparas in om materialen i småhus C används i stället. Småhus A är mer miljövänligt sett till koldioxidutsläpp än småhus B men sämre än småhus C, och ekonomiskt mer kostsamt än både småhus B och C. Det material som är den största faktorn både ekonomiskt och miljömässigt är valet av isolering i vägg och tak. Resultatet från enkätundersökningen om vanliga materialval i svenska småhus visade att det verkar finnas en branschstandard för materialval i småhus. / 21,7 % of Swedens’s domestic emissions in 2021 was represented by the building an real estate sector (Boverket, 2023a), which highlights a considerable potential to reduce emissions in line with UN:s sustainability goals. As well as companies, individuals also have the opportunity to contribute to a positive change by building more sustainable houses. This project aims to compare different materials choices in the building envelope of houses from a sustainability perspective. One of the analyzed alternatives is an existing newly built example house (house A) built with less common materials, which was compared to a conventional Swedish house (house B) based on a conducted survey. A literature study of common existing materials were the foundation for survey, which was sent to 53 construction companies were 31 companies responded. An alternative proposition (house C) was developed during the project with the goal of improving material choices from both an economic and environmental perspective.   A life cycle analysis has been conducted to evaluate environmental sustainability by studying carbon dioxide equivalent emissions during material extraction and production, transportation, and the use stage. A life cycle cost assessment has been used to analyze material and transportation cost. The economic and environmental aspects must be balanced in order for a solution to be sustainable. This can be achieved if the solution is environmentally friendly while also being economically justifiable. House C is based on the results of the life cycle analysis and life cycle cost from house A and B, as well as existing obstacles that were examined through literature and questionnaire that was sent to involved stakeholders in the building process. Two fictional house models were creates based on the average living area of small houses in Sweden. The result of the study was applied to these models to provide an estimate of the total CO2eq emissions and cost for a small house.      The obtained results showed that the cheapest option is house B, but it also generates the highest carbon dioxide equivalent emissions. For an additional cost of 105 000 sek or 124 000 sek for the fictional houses with an area of 122 square meters, 7,1 and 12,1 tons of carbon dioxide equivalent emissions could be reduced if the material propositions for house C is used instead. House A is more environmentally friendly with regards to house B, but less so than house C. On the other hand, it is more expensive then both house B and C. The biggest factor is the choice of insulation materials in walls and the roof, regarding both the economic and environmental aspect. The result of the survey on common material choices in Swedish small houses indicates that there seems to be an industry standard for material choices on these houses.
526

The life cycle and developmental phases of Cambrian-Ordovician organic-walled microfossils from Kolguev Island, Arctic Russia. / Livscykel och utvecklingsfaser hos kambrisk–ordoviciska organiska mikrofossil från Kolguev, arktiska Ryssland

Pazio, Magdalena January 2016 (has links)
Light microscopy studies of collections of late Cambrian/Early Ordovician organic-walled microfossils, informally called acritarchs, provide the observations on phenotypic traits that are comparable to Modern microalgae and make possible recognition of various developmental stages in their complex life cycle. The exceptionally preserved Saharidia fragilis microfossils show the internal body within the vesicle and the formation of the fringe and pylome, the opening for releasing of the daughter cells from the phycoma-like cyst. All the reproductive stages are distinguished and the hypothetical reconstruction of the complex life cycle is proposed. Various morphotypes are recognized to be a part of the class Prasinophyceae and some microfossils of the genus Leiosphaeridia are thought to represent the develop-mental stage of Saharidia fragilis life cycle. The morphological similarity suggests that those micro-fossils from the Cambrian-Ordovician transitional time interval are the ancestral representatives and early lineages of the Modern class Prasinophyceae. / Alger är idag viktiga producenter av fritt syre i atmosfären. I denna avhandling presenteras nya studier av encelliga organiska mikrofossil från den ryska ön Kolguev. Fossilens form och struktur (där många visar på en karaktäristisk rund öppning, så kallad pylome) ger en grund för att rekonstruera en komplex livscykel hos vissa av dessa kambrisk-ordoviciska taxa och tolka dem som alger. Studier med hjälp av ljusmikroskop utfördes i syfte att fastställa mikrofossilens funktionsmorfologi och fenotypiska drag. Dessa studier är viktiga för att klargöra biologiska släktskap och livscykeln av de studerade arterna.
527

INSTRUMENTATION AND LOGISTICS: INFLUENCING DESIGN AND OWNERSHIP COSTS

Phillips, Martin 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A program’s success is measured by the three parameters of cost, schedule and performance. This is true of any acquisition program, including instrumentation development and procurement. The primary purpose of Logistics is to influence and reduce the Total Ownership Costs (TOCs) to the Department of Defense while procuring a supportable system that meets the customer’s needs. The time to influence the TOCs is as early in the life-cycle of the program as can be done - where it is cheapest to affect a “fix.” This paper will briefly describe where Logistics influences ownership costs in the acquisition process. Examples of cost drivers identified in the Hardened Subminiature Telemetry Sensor System (HSTSS) program will be provided and the role of Integrated Product Team (IPT) members in influencing and reducing the TOCs will be discussed. This process is not just in the purview of the traditional logistician, but is also performed by each member of the program’s IPT. Each IPT member brings his unique knowledge and experiences to the teams pool of corporate knowledge. Examples will be provided of decisions made by the IPT that reduced TOCs.
528

全球化下韓商投資中國之策略 -以TFT-LCD面板產業為例 / Investment Strategies of Korean Businesses in China under Globalization: An Analysis of the TFT-LCD Panel Industry

孫正宇 Unknown Date (has links)
China has become both South Korea’s largest trading partner and one of the largest destinations for foreign direct investment (FDI). The display industry, which is one of the major export industries for Korea and extremely important for the Korean economy, has a particularly high level of dependence on China – the industry’s largest market. The Korean LCD panel industry has grown into a global leader and major industry of the Korean economy over the past ten years through its preemptive, aggressive investment and its development of innovative products. This was helped by the diverse strategies for aggressive investment in China that were implemented since the early 2000s as the companies faced unlimited competition in the global era. However, the rise of the Chinese LCD industry, which was spurred by the rapid growth of the domestic market and government support policies in the mid-2000s, has impacted the investment strategies of the Korean LCD panel industry in China. This research focuses on an analysis of the investment strategies of Korean TFT-LCD panel industry businesses’ investments in China in terms of their corporate and business strategies. It also assesses the status of the LCD industry and market, reviews the Korean LCD panel industry’s development, and analyzes its competitive strategy using Porter’s five forces model, industry life cycle, and the value chain. Based on the findings and the forecast for the Korean LCD panel industry, it then concludes by providing suggestions for the major industry players and the Korean government.
529

A study of thermal comfort and cost effectiveness of stratum ventilation

Fong, Alan Ming-Lun January 2015 (has links)
This studyh focuses on thermal comfort and cost effectiveness of stratum ventilation in subtropical Hong Kong Special Adminstation Region (HKSAR). The need for studying thermal comfort with various air distribution strategies becomes a significant issue recently due to climate change, increasing energy prices and the governmental energy efficiency policy. Stratum ventilation, with air supplied at breathing level, can probably provide satisfactory thermal comfort at a relatively elevated indoor temperature in which less energy use is consumed. It seems that only limited studies on the evaluation of neutral temperature, which is a condition of neither slightly warm nor slightly cool, are supported by actual human comfort surveys. Moreover, study on the related thermal comfort and cost effectiveness as other paradigms in comparison with the mixing and displacement air distribution design is rare. New environmental chamber of laboratory-based air-conditioning systems has been developed for investigating the actual benefit of cost effectiveness and balance of thermal comfort satisfaction with the stratum air distribution strategy under subtropical climates. American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 7-point questionnaires have been collected from human comfort tests so as to estimate the neutral temperature of stratum ventilation in comparison with mixing and displacement ventilation at pre-set conditions. The neutral temperatures of HKSAR people under the mode of mixing, displacement, stratum, modified-stratum-1, modified-stratum-2, and modified-stratum-3 are found to be 24.6℃, 25.1℃, 25.6℃, 26.0℃, 27.1℃ and 27.3℃ at 10 air change per hour (ACH) respectively, which become 24.8℃, 25.3℃, 26.6℃, 27.4℃, and 27.9℃ at 15 ACH respectively. Life cycle assessment results in 10 service year indicate that 7.73% and 7.32% of cost reduction, and 14.52% and 11.91% of greenhouse gas emission reduction in stratum ventilation by comparing with mixing and displacement ventilation. As a result, stratum ventilation should be the best option on both of cost reduction, and less carbon emission in small-to-medium size air-conditioned space for new building and retrofitting existing works.
530

Carbon and energy payback of variable renewable generation

Thomson, Rachel Camilla January 2014 (has links)
The continued drive to reduce Greenhouse Gas (GHG) emissions in order to mitigate climate change has led to an increase in demand for low-carbon energy sources, and the development of new technologies to harness the available energy in the wind, waves and tides. Many controversies surround these technologies, however, particularly with regards to their economic cost, environmental impacts and the implications of the variability of their output for security of the electricity supply. In order to make informed policy decisions on future developments of the electricity system, it is necessary to address these controversies and confirm the environmental, economic and social sustainability of these new renewable generators. This thesis specifically examines two key issues: whether new variable-output renewable energy generators actually deliver a net reduction in greenhouse gas emissions over their lifetimes, and whether they produce a viable energy return on energy investment. Although renewable energy sources are themselves ‘carbon free’, GHG emissions (and energy consumption) occur during the construction, maintenance and decommissioning of the generator infrastructure required to convert this energy into electricity. Furthermore, the variability of the output power from such generators has implications for the operation of the grid - there may be a requirement for additional reserve capacity and the increased part-loading of conventional plant is likely to reduce its operating efficiency. Carbon and energy paybacks are measures of the time required for a new renewable installation to offset these life cycle impacts. The work presented in this thesis examines both the life cycle impacts and the GHG emissions displacement of variable renewable generation, using Great Britain as a case study, in order to provide a basis for significantly more robust and reliable estimates of carbon and energy paybacks. The extensive literature survey concentrates on two key areas: current calculation methodologies and estimates for life cycle carbon and energy consumption of power generators; and the marginal emissions displacement of variable renewable generation. A detailed life cycle assessment of the Pelamis wave energy converter is presented, which sets the embodied carbon and energy in the context of the wider environmental impacts and includes an examination of the effect of different assumptions on the analysis results. In order to investigate the true emissions displacement of renewable generation, a historical analysis of real data from the National Grid was carried out, identifying the marginal displacement factor of wind power and taking into account the effect of the efficiency penalties of conventional plant. The findings of the analyses presented in this thesis are combined with information from the literature to examine the actual carbon and energy payback of existing renewable generation infrastructure on the British grid, and to provide detailed recommendations for future carbon and energy payback calculations.

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